$30 data plan question

So I have the $30 data plan thing for my curve that I just got today... My question is it unlimited web usage on my BB? I plan on using Pandora and it said it uses a lot of data... Will I be charged a lot for using it?

I just started using Pandora on mine about a month ago. I use it from 8AM to 5PM, periodically turning it off. I went from 15MB of usage a month to 1GIG. No problems. If you log into your account online it will tell you your usage and right below it will say its unlimited.